Checking e-mail has long been considered the primary pastime of the online user. However, if data from Nielsen is to be believed, that’s no longer the case. The firm found that on average, about 23 percent of our online time is spent on social networking sites, versus 8.3 percent on email.

This was a much wider spread than last year, when it was 15.8 and 11.5 percent respectively. The changes could be explained by the fact that social networking sites are the primary method of communication between friends these days, which makes sending an e-mail much less necessary.

Facebook is dominating this space, with an 85 percent share of social networking use. MySpace comes in a very distant second with a five percent share, and Twitter only a single percentage point.

Our third most popular activity online is playing games, which on average takes up about 10 percent of our time. Again, highlighting the power of social networking, Zynga is one of the biggest companies in the space.

Zynga is creator of the popular game Farmville, which has seen a majority of its success as a result of the success of Facebook itself.